1. Field of the Invention
This invention relates to a pneumatic tool, and particularly to a tool having a rear exhaust device with excellent intake and exhaust structure.
2. Description of the Prior Art
In the conventional pneumatic tool, the dynamic force to drive the tool is a compressed air, which enters the dynamic body portion to drive a rotor and blades therein, and then the air will be exhausted out of an exhaust hole. As soon as the compressed air enters the dynamic body portion, the blades will be driven to actuate the rotor to rotate; the rotor will actuate a spindle to turn so as to fulfil a work as expected.
In a conventional pneumatic tool, a compressed air enters a connection seat of the tool via a suitable pipe. By means of a valve, the compressed air enters the dynamic body portion of the tool to drive the blades and rotor so as to actuate a tool to turn or to move back and forth. Whether the blades and the rotor can work perfectly or not is depending upon the intake control assembly, the intake passage, and the exhaust passage to connect with the dynamic body portion; if the answer is "no", the dynamic output thereof is deemed poor.
In a conventional pneumatic tool, the dynamic body portion for the rotor and the blades is usually connected together with the cock and handle; the intake connector is directly screwed together with the intake end of the dynamic body portion. The rotor and the blades are mounted in the cylinder sleeve; a compressed air is used for driving the blades to turn, and then it will be exhausted via a passage of the dynamic body portion; it is called as front exhaust pneumatic tool; such a pneumatic tool usually causes considerable noise during working. Another kind of such tool has an exhaust passage formed between the inner wall and the cylinder sleeve, and extended to the rear end of the control valve. The outer end of the dynamic body portion is mounted with an outer pipe for exhausting air to the tail end, and such a pneumatic tool may be referred to as a rear-exhaust pneumatic tool; it usually has a lower noise during operation.
In the conventional rear-exhaust pneumatic tool, the handle is also used as the dynamic body portion thereof, and such structure can merely be used in some pneumatic tools, and it is unable to be used in a tool requiring increasing pressure.